Although aggression among girls was once thought to be relatively rare, more recent research suggests that girls frequently engage in relational aggression (e.g., manipulating relationships and social standing through gossip and social exclusion). Further, children who frequently exhibit relationally aggressive behaviors experience a host of externalizing, internalizing, and social difficulties, and are at risk for future mental health disorders. Despite advances in understanding relational aggression and its repercussions, almost all aggression intervention efforts have been designed for physical aggression and for boys. Further, given the increased risk experienced by African American students in inner-city, under-resourced areas, strategies for building the capacity of inner-city schools to promote the development of productive social problem solving skills while decreasing students' levels of relational and physical aggression are critically needed. With funding from NIMH (K23 Award), the principal investigator has designed an intensive 20th session school-based group intervention, which includes a 12 session adjunctive classroom-based component. The goal of this program, termed Friend to Friend (F2F), is to teach 3rd - 5th grade inner-city African American relationally aggressive girls social problem-solving skills and reduce their levels of aggression. The current proposal seeks to develop a classroom-based intervention termed Preventing Relational Aggression in Schools Everyday (PRAISE) that expands upon the classroom-based curriculum of F2F. In phase 1, PRAISE will be developed and fine-tuned through focus groups with students and teachers, by relying upon an expert panel of local school and community stakeholders, and by conducting an open trial pilot study. In phase 2, the acceptability and feasibility of PRAISE for use within a classroom setting will be assessed, effect size estimates for the impact of PRAISE on relationally aggressive girls within experimental classrooms will be derived, and potential effects of the intervention at the classroom level will be preliminarily explored.